The present invention relates to an adjustable needle mechanism finding particular use in combination with an endoscope.
Endoscopes are used with injection needles to inject gastrointestinal mucosa with liquid reagents to achieve desired effects. For example, sclerosants may be injected for esophageal vatices and epinephrine may be injected to control bleeding. In order to accomplish such treatment, a needle mounted on the end of a long tube may be passed through a channel of the endoscope to inject the desired objective. The needle is shielded by a catheter within which the needle and tube are received. When the endoscope is properly located at the injection site, the needle is projected from the end of the catheter and the injection is effected.
It has been found that the length of the catheter and the tube can be affected between the time of manufacture of the mechanism and the time of use in the endoscope. For example, when the mechanism is sterilized the catheter may be lengthened or shortened or the tube may be lengthened or shortened resulting in the mechanism not projecting the needle sufficiently for proper injection of reagent. Such a problem may require the user of the mechanism to trim back the catheter before use.
Thus, the time of hospital personnel is not used effectively and damage to the mechanism may result.
It is an object of the present invention to provide an improved gastrointestinal needle mechanism. A further objective is to provide a needle mechanism which eliminates the need for trimming the catheter.